The present invention relates to electrochemcial devices. Electrochemical devices are typically made of thin electrode and separator layers.
An example of such an electrochemical device is described in Kejha et al U.S. Pat. No. 5,521,023. Kejha et al. describes using a sheet of perforated plastic material along with a liquid ion-conductive polymer. The ion-conductive polymer is cured to form a solid- or semi-solid-state electrolyte composite. The perforated plastic material helps maintain the separation between the electrode layers. The liquid ion-conductive polymer by itself may not sufficiently maintain the separation between the electrode layers.
Another manner of maintaining the separation between the electrode layers is to use a separator using a co-polymer/plasticizer separation layer. The co-polymer/plasticizer layer can be laminated to electrode layers. The co-polymers of the separator will mix with co-ploymers of the electrodes. Later, the plasticizer is removed and an electrolyte solution added. The electrolyte solution provides and ion-conductive path between the electrodes. The co-polymer of the separator provides a relatively constant separation distance for the separator. The co-polymer remains not significantly soluble in the electrolyte solution, so that separation of the electrodes is maintained.
It is desired to have an improved electrochemical device.